Seismocardiographic (SCG) devices and methods are known in the art. In general these devices use an accelerometer to monitor the patient's heart. In use, an accelerometer is placed on the surface of the patient to detect compression waves originating in the patient's heart. The compression waves received by the accelerometer are digitized and analyzed with a computer. These SCG devices may be used for cardiac monitoring and diagnostic purposes. In some instances the SCG is used as a replacement for electrocardiographic monitoring of heart rate. In the present invention the system is used to find time intervals between mitral valve opening (MO) and mitral valve closure (MC) times, as well as the opening time (AO) and closing times (AC) for the aortic valve. The time intervals may be used to compute classic measures of cardiac performance including the isovolumic contraction time and the left ventricular ejection time (LVET). At the present time such measures are made with echocardiography.